The present invention relates to a system for detecting, exchanging and storing data in a motion picture camera cassette.
U.S. Pat. No. 4,627,695 discloses a motion picture camera cassette system which has automatic measurement and display of exposed and unexposed film in one of a plurality of exchangeable film cassettes which can be connected to the camera body of a motion picture camera. For this purpose, each film cassette has for identification purposes a cassette code which is assigned exclusively to this film cassette. The motion picture camera has a device for reading and identifying the cassette codes, and a memory with a plurality of memory areas each of which are assigned to an individual film cassette, and which stores the length of the exposed or unexposed film in the film cassette which is assigned to the memory area. In addition, the motion picture camera has a microprocessor that receives the cassette identification signals and to which measuring pulses are fed which are output by a pulse generator connected to the film motor for each film image running through the film gate of the motion picture camera.
In this known motion picture camera cassette system, the motion picture camera stores and varies the length of the exposed or unexposed film of a film cassette which only has an identification mark that is detected by the motion picture camera. This is disadvantageous because the number of the film cassettes which can be connected to the camera and can be identified by the camera depends on the length of the identification mark and on the size of the camera memory. The length of the identification mark in turn determines a corresponding number of markings on the film cassette and sensors for detecting the identification marks on the side of the motion picture camera.
A further disadvantage of the known motion picture camera cassette system is that the various film cassettes are respectively assigned to only one motion picture camera. If a specific film cassette is connected to another motion picture camera, either it is necessary for the data to be acquired in advance from the motion picture camera originally assigned to the relevant film cassette and input into the memory of the other motion picture camera, or to load the film cassette with an unexposed film of known length.
A further disadvantage of the known system is that it is possible to exchange data with a data-processing device used in film production only via a connection to the motion picture camera. In this case, cassette data, film data and production-specific data cannot be detected, stored and further processed, or can only be detected, stored and further processed with considerable outlay.
It is an object of the present invention to create a motion picture camera cassette system that permits the detection, storage and transmission of data between a plurality of motion picture cameras, film cassettes and data-processing device in any desired way and preferably via an individual data line.
The solution according to the invention permits data to be exchanged between an arbitrary number of film cassettes, with optionally differing motion picture cameras, and data-processing device, and permits data to be transmitted preferably via a single data line.
In addition to individual marking of the film cassettes and storage of the respectively exposed or unexposed film length of the relevant cassette, the memory device contained in each film cassette also permits further data of importance for film production, such as a production number, film type, film sequence, etc., to be input and stored.
By storing film data, cassette data and production-specific data in each film cassette, the data can optionally be input and displayed directly on the film cassette, on a motion picture camera or on a display of a data-processing device.
The electronic data-processing device serves, in particular, to process, document and display the data output by a motion picture camera or a film cassette, and can, for its part, transmit data, such as, for example, when loading a film cassette, the length of the inserted, unexposed motion picture film, into the storage device of the film cassette, the input of a production number both into a motion picture camera and into a film cassette connected to or separate from a motion picture camera.
The data is exchanged between motion picture camera, film cassette and electronic data-processing device preferably via an electrooptical or magnetic transmitting device or via an electric line connection. Only one data line is required for serial data transmission.
It is preferable to use as an interface on the motion picture camera an interface which is present there in any case, such as, for example, a time code interface, an interface for a video reflex monitor or the like.